1. Field of the Invention
The field of invention as established in and by the U.S. Patent Office is believed to be in the general class entitled "Surgery" and in the subclass pertaining to syringes used to introduce and remove liquid material from a body. More particularly, this invention is directed to a cover or protector of the sharpened tip of a needle in which the protector is moved in response to the advancing insertion and withdrawal of the needle into a patient.
2. Description of the Prior Art
The covering of the sharpened tip end of a needle to protect the attendant has been the subject of many patents extending back for more than thirty years. Among these patents are: U.S. Pat. No. 2,876,770 to WHITE as issued on Mar. 10, 1959. Also noted are: U.S. Pat. No. 2,925,083 as issued to CRAIG on Feb. 16, 1960; U.S. Pat. No. 3,040,743 as issued to NAESS on June 26, 1962; U.S. Pat. No. 3,306,290 issued to WELTMAN on Feb. 28, 1967; U.S. Pat. No. 3,406,687 as issued to MOYER on Oct. 22, 1968, and U.S. Pat. No. 4,425,120 as issued to SAMPSON et al on Jan. 10, 1984. These patented devices propose to provide a tip protector that prevents exposure after use.
At present, a molded cap or thimble is placed on each of the needles used with syringes. These caps prevent accidental pricking of the needle into an adjacent member. When and after the needle is exposed with removal of this cap, the sharp end is and remains exposed. Prior to the advent of Hepatitis and AIDS, the worry of the attendant was a prick, which may or may not have been uncomfortable. With the danger of infection from Hepatitis and AIDS, protection from a prick or penetration by the sharpened tip is mandatory.
The patent to WHITE utilizes a rigid shield with a spring urging the shield to its outward condition. Manual manipulation and a bayonet-type lock are also employed to maintain the shield in a retracted condition. CRAIG also provides a rigid shield and a spring. When the shield of CRAIG is moved to needle-exposed condition, a latch is utilized to release the shield. WELTMAN builds the rigid needle protector into the syringe housing, with the needle and syringe a reusable product. These patents show needle protectors with spring means, but all are expensive and contemplate rigid shield members. The present invention is adapted for use with the disposable syringes now used and with the sharp needle tip being protected immediately, when withdrawal from the patient is made.